1. Technical Field
This invention relates to electrical connectors for fluorescent lamps, and particularly to a connector for a circle-line type of fluorescent lamp in which a glass tube is formed in a circle, with the ends of the tube joined by a socket having four projecting electrical contact pins arranged in a rectangular pattern.
2. Background Art
One style of conventional four terminal female connector for circular fluorescent lamps is disclosed in U.S. Pat. No. 3,292,097 issued to E. G. Gaynor on Dec. 13, 1966. The connector shown in this patent includes a body member having four longitudinally extending terminal-receiving passages and a cap fitted into a recess in the body member to enclose the terminal passages. Each terminal is formed from a metal strip and has an elongated flat base extending the length of the terminal, a pair of converging clamping arms extending from the base at one end of the terminal adjacent to an opening in the end of the body for receiving a corresponding prong of a fluorescent lamp, and a pair of diverging arms extending from the base at the other end of the terminal.
Electrical leads extend through openings in the cap and are soldered to the other end of each terminal. The cap is fastened to the body by a screw, and the diverging arms serve to lock the terminals against the inner face of the cap to withstand any pull on the electrical leads.
The soldered-lead connector of the Gaynor 3,292,097 patent has been superseded by a push-in style of connector in which each electrical lead is frictionally engaged by a hooked end of the corresponding terminal, which holds the lead, by a wedging action, against being pulled out after insertion.
The newer style connector includes a molded plastic terminal support having a body formed with four parallel elongated terminal-receiving open channels. The body slides into a molded plastic housing, which locks to the body by a snap fit between an integrally molded protrusion on the body and a mating recess in the housing.
Each terminal of the new style connector is formed from a metal strip having parallel longitudinal edges, with a pair of converging arms extending from the longitudinal edges at one end to form a prong-engaging portion similar to that shown in the Gaynor 3,292,097 patent.
The remainder of the metal strip, which forms a base for the terminal, extends from the prong-engaging portion and includes a stepped offset portion, a flat longitudinally extending portion, and a bent-back hooked end. The offset portion fits in a transverse gap between first and second longitudinally extending flange-like members on the body of the terminal support, the flat portion fits along an outer surface of the first flange-like member, and the hooked portion fits around the first flange-like member at one end of the terminal support body and extends at an acute angle into the terminal-receiving channel. The prong-engaging portion is also disposed in the terminal-receiving channel adjacent to the other end of the channel, with its axis parallel to the channel axis.
The newer style connector provides manufacturing economies over the earlier Gaynor 3,292,097 connector by eliminating the soldered lead connections. Also, the offset design of each terminal base, allowing the hooked end of the terminal to be fitted around the outside of the above-described first flange-like member provides a secure mounting for the terminal to resist both longitudinal and transverse movement in its channel.
It was found, however, that the new style of four terminal female connector was commercially unacceptable because of interference between the prong-receiving portion and male prong-type connectors due to lumps of solder that are often left on the tips of the prongs during the lamp manufacturing process. It is an object of the present invention, therefore, to provide a four terminal female connector of improved design, which retains the advantageous rigidity of "wrap around" terminal mounting yet eliminates any possibility of interference when the connector is assembled to the prongs of a lamp.